Slag, such as produced by a blast furnace, is a valuable byproduct of a smelting operation. For storage, transport, and use of slag it must be converted from its molten viscous form into granules of manageable particle size. Typically the molten slag is mixed with water which serves simultaneously to chill it and break it up into granules. A typical granulation process, such as described in commonly owned U.S. Pat. No. 4,123,247, produces a so-called fluent slag slurry, that is a mixture of slag granules and water.
It is necessary to separate the water from the granulated slag so that this granulated slag can be stored, transported and used. In a common method for doing this the slag slurry is poured into a large basin where the heavier granules sediment out so that the water can be decanted or poured off. The granules are then removed from the basin by a skip loader, shovel arrangement or other mechanical means.
It is also known to pump the slag up into a tall hopper having a foraminous floor. The water in the slag can slowly drain from it, passing slowly through the relatively thick layer of slag granules in the hopper.
Both of these arrangements have the considerable disadvantage that they take up a great deal of space. As both processes rely on sedimentation of a large mass of the slurry, they take considerable time so that several basins or hoppers must be provided if slag slurry is being produced continuously. Obviously the space is not available for such an installation in conventional smelting plants. Furthermore the considerable handling that the relatively brittle slag granules are subjected to in such arrangements produces a considerable percentage of useless fines of unmanageably small particle size.